Reducing noise of load sensor

Hi,
I have a 4 50kg load sensors like this. They are half bridge and are usually connected in pairs together to make two full bridges to be measured. I want to have the sensors quite far away from each other, something between 1 and 2 m. I am afraid the large distance introduces possibility for lot of noise. Is it worth to add two resistors to each sensor to make 4 bridges instead and place the ADC as close as possible to each sensor? Or is the noise negligible if I twist the wires?

That isn't very far at all.

Until you can characterize the noise, there is not much you can to to eliminate it, is there? Twisting wires only works for differential noise, noise picked up in one wire and not the other, or phase difference. Twisting ensures both wires get the same noise an can be canceled out on one end.

Twisting makes no difference for common mode noise, the same noise, same phase, on both wires. Common mode noise is reduced by using ferrite cores and wrapping several turns of the pair through the core.

Best way to avoid the noise, if it exists, is to put the wires in metal conduit.

Paul

Paul_KD7HB:
That isn’t very far at all.

Are you sure? It is said IIC wires should be short (better not to leave the PCB). I know it is very different situation but when IIC with noise margin of at least 1V may have problems with noise what about my load cell where differences in tens of uV are important?

Paul_KD7HB:
Twisting wires only works for differential noise, noise picked up in one wire and not the other, or phase difference. Twisting ensures both wires get the same noise an can be canceled out on one end.

Twisting makes no difference for common mode noise, the same noise, same phase, on both wires. Common mode noise is reduced by using ferrite cores and wrapping several turns of the pair through the core.

I am interested in differential measurements so I think common mode noise is not so important. But maybe unchecked common mode noise may be so large it is important even despite large CMRR any defferential ADC should have - I have no idea.

Paul_KD7HB:
Until you can characterize the noise, there is not much you can to to eliminate it, is there?

I have no idea what may be source of the noise. I hoped to do “everything reasonable” to reduce possible noise and it will be OK. I live in a city so it is safe to assume there is a lot of noise on all possible frequencies. For example I can light a LED with mere touch.

IF you intend to continue to work with electronics then you MUST invest in proper test equipment such as an oscilloscope that can show you an image of the noise. And then you can do things to reduce it and see visually the results.

I can't explain the LED either. You can, with proper equipment, solve that mystery, also.

Paul